Fair Value Of Financial Instruments (Schedule Of Assets And Liabilities, Measured At Fair Value) (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	[1]	$ 8.2	$ 14.6
Restricted cash and cash equivalents	[1]	255.6	224.7
Restricted securities available for sale	[2]	46.1	45.3
Net investment in Loans receivable	[1]	4,741.5	3,955.9
Revolving secured line of credit	[1]	13.9	0.0
Secured financing	[1]	2,527.6	2,072.0
Senior notes	[1]	569.4	560.5
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	[1]	8.2	14.6
Restricted cash and cash equivalents	[1]	255.6	224.7
Restricted securities available for sale	[2]	37.1	37.1
Net investment in Loans receivable	[1]	0.0	0.0
Revolving secured line of credit	[1]	13.9	0.0
Secured financing	[1]	0.0	0.0
Senior notes	[1]	569.4	560.5
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	[1]	0.0	0.0
Restricted cash and cash equivalents	[1]	0.0	0.0
Restricted securities available for sale	[2]	9.0	8.2
Net investment in Loans receivable	[1]	0.0	0.0
Revolving secured line of credit	[1]	0.0	0.0
Secured financing	[1]	2,527.6	2,072.0
Senior notes	[1]	0.0	0.0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	[1]	0.0	0.0
Restricted cash and cash equivalents	[1]	0.0	0.0
Restricted securities available for sale	[2]	0.0	0.0
Net investment in Loans receivable	[1]	4,741.5	3,955.9
Revolving secured line of credit	[1]	0.0	0.0
Secured financing	[1]	0.0	0.0
Senior notes	[1]	$ 0.0	$ 0.0

[1] at amortized cost with fair value disclosed.

[2] Measured at fair value on a recurring basis.